When Do You Stop Protecting a Superstar? The Bill O'Reilly case highlights the widespread damage that even a media star can wreak.

After a series of sexual harassment allegations, Fox News fired Bill O'Reilly last Wednesday. As a staple of the network for more than 20 years, O'Reilly was Fox's most popular and lucrative personality.

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But then a report in the New York Times revealed that five women had been paid a total of $13 million to stay quiet about their harassment allegations against O'Reilly. Only after the Times article report did Fox formally sever ties.

In fact, Fox's relationship with O'Reilly, and the network's persistence in protecting his position, tells a larger story about companies that cling to toxic employees.

"This is a symptom of a much larger problem in many of the world's top companies," Todd Mitchem, whose title is managing disruptor at the executive coaching firm Todd Mitchem Companies, in Denver, told me. "Often, an organization will favor commercial success over cultural success in the name of the bottom line. But they fail to realize, as in the case now with Fox News, that holding on to a commercially successful person who ruins a culture can actually prove to be far more painful in the long term."

There are many variables that play into how Fox could have handled the situation with O'Reilly differently. Key groups like human resources, public affairs, O'Reilly's manager, his peers and the network's head of ad sales all had stakes in the outcome of the harassment scandal.

"Many different people were clearly affected by this situation," Julie Zadow, CMO of TalentFirst in Bridgewater, N.J., told me. "But where were the leaders who bore a moral responsibility to address this sooner?"

The message from Fox's handling of the O'Reilly situation, then, seems to be this: Organizations need to cut ties with toxic employees sooner than later -- or risk further damage to company culture, revenue and reputation.

What "toxic" looks like

Typically, toxic superstar employees are not difficult to identify. Unfortunately, however, denial holds employers back from pinning down those criteria. If a high-performing employee is making an impact on the bottom line, it's hard to admit that he or she is problematic in other ways.

Here are a few signs to watch for:

Above-the-law mindset. Ilene Marcus, CEO and founder at Aligned Workplace in New York City, described how she once hired a new director of major gifts. "Her fund-raising techniques were legendary," Marcus told me. "In her first month, she brought on two new major donors, each committing $1 million."

However, the director's star power was not enough to shield her from the negative impact she had on the company culture. "In our business, even the stars crunch their own data, and our star refused to do this," Marcus said. "I was in a bind with a high performer who was bucking the work culture."

Taking credit where credit is not due. Another example comes from Bryan Clayton, CEO of GreenPal in Nashville, who previously hired an operations manager who seemed at first to be a self-starter and perfect fit for the company. Clayton eventually learned this employee was taking credit for the work of other team members.

Related: 3 Toxic Employees You Need to Fire Now

"Of course, I did not want to believe it," he told me. "She was my girl, my pick; if she was a failure, then I was a failure for picking the wrong person, right?"

Negative workplace behaviors. Zadow, on the other hand, spotted her toxic employee right away. "He was, on a daily basis, rude, condescending, short-tempered, entitled and mean-spirited to all of his fellow employees," she told me. However, the process of replacing him hindered any action from management -- and ultimately backfired.

"Many of our roles took months and months to refill, creating lag time on projects and costing the business time, profits and results," Zadow said. "Other very valued employees quit and took their talents elsewhere rather than choosing to work with this person any longer."

Sexist tendencies. Then, of course, there are the employees like O'Reilly who are toxic to women in the workplace. "I worked with a man who was super sexist and treated women as objects," Bruce W. Cameron, a clinical and forensic counselor in Dallas, told me. "This lasted for years until someone had the courage to speak up."

There are a number of ways for leaders to be both proactive and reactive when dealing with toxic employees once they are identified. Here's how:

Step 1: Conduct interviews proactively.

Strategic interview questions can be a strong starting point for weeding out toxic new hires. Ask situational questions that call for examples of how the candidate would handle a specific situation.

"We changed to scenario-based interviewing," Marcus told me, "to see how far our culture would need to bend, and how far off the reservation this person may go.

"Keep in mind that interviews are a great initial judge of character but that toxic superstars will be on their A-game, so [those interviews are] not foolproof. You often can't predict it from the outset," Marcus added..

Laurence J. Stybel, CEO of Stybel Peabody Associates, Inc. in Boston, agreed. "Doing a job interview is a learned skill, like playing tennis," he told me. "The O'Reillys [of the world] really know how to do a great interview, and make sure they have great references. The critical thing is to create a culture that does not bow to obnoxious superstars."

Step 2: Enforce company policies.

Once employees are hired, it's essential to actually enforce the policies in place, rather than avoid confrontation or consequences.

"Culture fit is everyone's issue and yet no one's responsibility," Marcus said. "In a very public situation, if the leader or CEO doesn't step up, action will not be taken."

When a high-ranking employee at Jacqueline DuJour Enterprises in Somerset County, N.J., sexually harassed another employee, the offender received a written warning on his employment record, with the understanding that any repeat offense would result in termination.

"Having witnessed the policy actually being implemented, I believe, shocked many," CEO Jacqueline Miller told me. The reason, she said, is that "employees, especially some men, look down their noses at HR issues as being a nuisance."

Consistent enforcement is the best way to hold employees accountable and maintain a positive workplace culture.

Step 3: Take action quickly.

When Autumn Manning, CEO of YouEarnedIt, in Austin, faced a toxic employee, she admits, her biggest mistake was not taking action in the moment.

"When I finally let this employee go, I met with the entire company to apologize for not taking action sooner," Manning told me. "I used the time to reinforce our culture and expectations of everyone and reinforce the vision and what we were there to accomplish. I had some trust-building to do, which was important."

In the interest of its bottom line, Fox News did not take action right away, which resulted in a lot of negative press and a hit to company culture. Had it reacted immediately -- and in opposition to O'Reilly -- it might not have lost that trust.

Step 4: Be engaged.

"Managers can avoid these pitfalls by making sure they are regularly meeting with their employees, capturing and providing feedback and helping employees understand not just the goals and outcome required for success, but the kind of demeanor and civility expected from all team members to ensure good team dynamics and healthy collaboration," Zadow told me.

Related: 12 Ways Successful People Handle Toxic People

Stay in tune with what's going on in your organization to avoid missing the warning signs of a toxic employee. Catching the problem, and taking disciplinary action as quickly as possible will benefit your workplace culture -- and therefore yourcompany's revenue and reputation.